Lead fuse for electric circuits.



Patented Sept. I6, I902.

No. 709,334. I

F. H. KREBS. LEAD FUSE FOB ELECTRIC CIRCUITS.

(Application filed Oct. 26, 1901.)

(No Model.)

UNITED STATES PATENT OFFICE.

FREDERICK HENRY KREBS, OF COPENHAGEN, DENMARK.

LEAD FUSE FOR ELECTRIC CIRCUITS.

SPECIFICATION forming part of Letters Patent N 0. 709,334, dated September 16, 1902.

Application filed October 25, 1901. $erial No. 79,953. (No modeLl To aZZ whom it 12mg; concern.-

Be it known that I, FREDERICK HENRY KREBS, a subject of the King of Denmark, residing at Romersgade 3, Copenhagen, in the Kingdom of Denmark, have invented a new or Improved Fuse-Plug for Electrical Plants, of which the following is a specification.

My invention relates to fuse-plugs for electrical constructions; and the object of the invention is to do away with the metal lining, thus cheapening the manufacture, and to so construct the fuse-plugs that they can be easily repaired when the wire is melted through. Heretofore when the wire has been melted new plugs have generally been used, the repairing of the old plugs being almost as expensive as the procuring of new ones.

The invention consists of novel features and parts and combinations of the same, as will be more fully described hereinafter, and then pointed out in the claims. I

The invention is shown in the accompanying drawings, forming part of this specification, in which Figure 1 is a side view of the fuseplug, partly in section. Fig. 2 is a longitudinal section through the body of the plug. Fig. 3 is a side view of the fusible wire and contactplate. Fig. 4 is a plan view of the same, and Fig. 5 is a view showing the lock-grooves for the hooks of the contact-plate.

The fuse-plug consists of a hollow body a, of china or other suitable insulating material, the upper part of which resembles the fuseplugs now in use. The body has a conical opening Z) in its lower end, and the body is provided at its outside with two slots or grooves c, Fig. 1. A contact-plate e is employed, to which the wired, of lead or other fusible metal, is connected, and this contactplate has oppositely-arranged arms or wings provided with hooks f.

The grooves c of the body of the plug are adapted to be engaged by the hooks fand form with said hooks a bayonet-joint to fasten the contact-plate e to the body when the plate is turned.

The grooves 0 have an inclined surface, as shown in Fig. l, and the upper part of the incline may be provided with depressions, (see Fig. 5,) which receive the hooks and hold the contact-plate e in position. A ring can be arranged around the lower part of the device to press the hooks of the contact-plates into the grooves.

The hole I) through the bottom of the body a is made conical, as shown in Fig. 2, in order to facilitate the insertion of the wire (1 and to readily receive the lower end of the wire, which at its junction with the plate e is somewhat enlarged.

The diameter of the opening I) at the top is just sufficient to permit the wire employed to pass through. This serves to prevent the gypsum g, molded into the plug, (see Fig. 1,) from passing through the hole and also prevents the employment of a wire too thick to give the desired result.

The upper end of the wire cl can be fastened to the ordinary copper contact 7L by soldering or in any other convenient manner, after which, as already mentioned, gypsum can be molded into the device in the usual manner.

The repairing of a fuse-plug the wire of which is burned through is very easily performed in the following manner: First, the fuse-plug is pressed against a revolving conical cutting'lile in order to loosen the gypsum, and the dust is brushed out by means of a metal brush. A new contact-plate c, with a fusible wire d, is then placed in position, as above described, the end of the wire is fastened to the contact h, gypsum is molded in the plug, and the device is ready for use.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. A lead fuse-plug for electrical plants, comprising a hollow body provided in its lower end with a hole of conicalshape, a lead wire provided with a contact-plate and adapted to be inserted in said body through said conical opening, theupper end of the wire being arranged for connection with a copper contact, as set forth.

2. A lead fuse-plug for electrical plants, comprising a hollow body having a conicalshaped opening in its lower end, a lead wire adapted to be inserted through said opening, and arranged for connection at its upper end with a copper contact, and a contact-plate connected with the lower end of the said wire and provided with hooks adapted to be fastened to the body by a bayonet-joint, as set forth. a

3. A lead fuse-plug for electrical plants, comprising a hollow bodyhaving a conicalshaped opening in its lower end, the diameter of the opening at its inner or apex end corresponding to the predetermined diameter of the wire required for the purposes of the plu g, thereby preventing the insertion of a wire of greater diameter, and a lead wire provided at one end with a contact-plate and adapted to be inserted in said plug through said opening, the other end of the wire being arranged for connection with a copper contact, as set forth.

4. As an article of manufacture, afuse-plug for electrical apparatus, comprising a gobletshaped insulating member provided with a smallaperture,a metallic jacket secured upon said goblet-shaped member, a disk provided centrally with a fuse-wire for passing through said aperture and provided circumferentially with anchors, and means for securing said anchors upon said goblet-shaped member.

5. As an article of manufacture, a fuse-plug for electrical apparatus, comprising a hollow insulating member provided with an aperture of arbitrary size, and means located adjacent to said aperture for the purpose of engaging the ends of a fuse-wire passing through said aperture, the said arbitrary size of said aperture being such as to exclude the passage of fuse-wires exceeding a certain size.

6. As an article of manufacture, a fuse-plug for electrical apparatus, comprising a hollow insulating member provided with openings and with a passage of arbitrary area in crosssection, and means adjacent to said passage for engaging the ends of a fuse-wire to be threaded through said passage, the said passage constituting a wire-gage and preventing the admission of undesirably large fuse-wires.

7. As an article of manufacture, a fuse-plug for electrical apparatus, comprising an insulating member provided with openings, and also provided with a narrow passage constituting a wire-gage, and means for connecting 8. As an article of manufacture, a fuse-plug for electrical apparatus, comprising an insulating-section provided with aconical opening and with one member of a bayonet-joint, a disk provided with the other member of said bayonet-joint, and also provided with a fusewire having a conical portion, a metallic contact secured upon said insulating-section, and means for securing said fuse-wire to said section.

9. As an article of manufacture, afuse-plug for electrical apparatus comprising a hollow insulating member provided with a conicalshaped passage constituting a wire-gage, and means for connecting a fuse-wire so that the latter will pass through said gage.

10. As an article of manufacture a fuseplug for electrical apparatus, comprising an insulating member provided with a conicalshaped aperture, the opening at the inner or apex end of the aperture being of arbitrary size, and means for engaging the ends of the fuse-wire passing through said aperture.

ll. As an article of manufacture, a fuseplug for electrical apparatus comprising an insulating-section having an opening for the passage of the fusible wire, the said section being provided with one member of a bayonet-joint, and a contact-plate carrying the fusible Wire and provided with hooks forming the other member of the bayonet-joint.

12. As an article of manufacture a fuseplug for electrical apparatus, comprising an insulating member provided with a conical opening and having one member of a bayonetjoint, a contact-disk provided with hooks constituting the other member of the bayonetjoint, and a fuse-wire connected at one end with said disk and adapted to pass through the said conical opening. i

In Witness whereof I have hereunto set my hand in presence of two witnesses.

FREDERICK HENRY KREBS.

Witnesses CHARLES F. LURCOTT, J. F. SMITH. 

